This protocol will treat patients with locally advanced or metastatic prostate cancer or renal cell carcinoma which expresses HER2/neu antigen and were not treated effectively by other regimens with GM-CSF and MDX- H210 antibody. GM-HGSF will be used to augment monocyte and neutrophil function. MDX-H210 antibody is an F(ab) X (ab) bispecific molecule comprised of anti-Her2/neu murine antibody and anti-FCgamma RI antibody. This antibody will theoretically bring effector cells together with tumor targets. A treatment cycle will consist of GM-CSF given on days 1-4, 8-10 and 15-18 as an outpatient and MDX-H210 given on days 4,11 and 18. After a 21-28 day rest period, the cycle will be repeated unless the patient has progressive disease.